Decorations are made at the Workbench, and are used to decorate Cornerstones, Club Worlds & player-made Dungeons and Lairs .  Decorations are split into tabs and sorted by Biome, and some Decorations must be learned from recipes before they're made.  Most decorations require Glim and a Biome-specific crafting material to make.  

Some rare decorations are drops, such as the Bears & Birds.